Complete Question
The complete question is shown on the first uploaded image
Answer:
The velocity is in positive x -direction
The speed is
Explanation:
From the question we are told that
The distance from the house to truck is D = 20 m
The distance traveled back to retrieve wind-blown hat is d = 15
The distance from the wind-blown hat position too the truck is k = 20 m
The total time taken is t = 75 s
Generally when calculating the displacement the Justin's backward movement to collect his wind - blown hat is taken as negative
Generally Justin's displacement is mathematically represented as
=>
Generally the average velocity is mathematically represented as
=>
=>
Generally the distance covered by Justin is mathematically represented as
=>
=>
Generally Justin's average speed over a 75 s period is mathematically represented as
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=>
Answer:
time rising = 34 / 9.8 = 3.47 sec
total time in air = 2 * 3.47 sec = 6.94 sec
(time rising must equal time falling)
R = 17 m/s * 6.94 s = 118 m
Can also use range formula
R = v^2 sin (2 theta) / g
tan theta = 34 / 17 = 2
theta = 63.4 deg
2 theta = 126.9 deg
sin 126.9 = .8
v^2 = 17^2 + 34^2 = 1445 m^2/s^2
R = 1445 * .8 / 9.8 = 118 m agreeing with answer found above
Use conservation of momentum ;
m1u1 + m2u2 = m1v1 + m2v2
1200×15.6 + 0 = 2700v
v = 18720/2700
v = 6.933 or ~ 7 m/s
The answer is Entropy or part C.
Entropy is basically a thermodynamic quantity that tells the randomness of a system or as said in the question tells us a measure of the disorder of the system.
The second law of thermodynamics states that a closed system has entropy which may remain constant or otherwise might increase.
It is basically the measure of the change of a system or universe when it goes from order to disorder.
Answer:
Explanation:
In the first case you can use the expression for the Doppler effect when the source is getting closer and getting away
( 1 )
( 2 )
f' = perceived frequency when the source is getting closer
f'' = perceived frequency when the source is getting away
f = source frequency
v = relative speed
vs = sound speed
by dividing (1) and (2) you have
but this is the relative velocity, you have that
a. hence, the speed of the police car is 102.5m/s